Many kinds of cancer resist effective chemotherapeutic treatment. In ovarian cancer, resistance is observed towards chemotherapeutic agents such as cisplatin. Cisplatin (cis-diamminedichloroplatinum, or CDDP), discovered originally in the late 1960s, is a cytotoxic drug used to treat many cancers, including ovarian cancer. Cisplatin acts by platination of DNA, resulting in DNA crosslinking. Up to 50% of ovarian carcinomas are intrinsically resistant to conventional chemotherapeutic agents such as cisplatin or other related platinum therapies. Many mechanisms of resistance have been postulated. However, the precise mechanism(s) underlying the intrinsic and extrinsic resistance to chemotherapy has not been elucidated. One method of reversing resistance to chemotherapy involves the use of chemosensitizers. Chemosensitizers generally inhibit the mechanism of resistance. Examples include verapamil, reserpine, tamoxifen and cremophor, inhibitors of efflux pumps conferring multidrug resistance (MDR1, P-glycoprotein). However, such chemosensitizers are effective only in a subset of tumors where drug efflux is the main mechanism of resistance. In addition, a number of these chemosensitizers have undesirable side effects.